An interesting article on how engineers create sounds for products to match our expectations. When we expect a certain sound, such as the noise of a car door closing, silence is very unsatisfying. So to compensate for this, engineers play the role of sound designers and create the sounds artificially to add them back in to the products.

But when manufacturers had to put extra bars in their side doors to comply with new safety standards the sounds of their doors started to change.

To compensate for the added weight they had to make other parts of the car lighter and took weight from the catches and door mechanisms. As a result, doors no longer made a satisfying clunk but had a tinny sound.

“They thought ‘How can we go about re-engineering the sound so it sounds more expensive and more high quality?’,” explained Prof Cox.

Manufacturers then started experimenting with different sound effects. Dampeners were introduced into the door cavity to muffle the tinny effect and engineers altered the locking mechanism to make just the right sort of click.

Another example not listed in the article is the ambient noise on a cellphone. Despite the fact that it’s perfectly possible to have digital cellphone audio be almost silent, a small amount of ambient white noise is added to the signal when there is silence on the other end to reassure us that we’re still receiving audio from the other side. It also has the benefit of letting you know when your call is about to be dropped by your carrier when it’s preceded by a few seconds of dead silence!

Side note: For a really cool look at what sound designers add to a movie, check out these featurettes from the Indiana Jones DVD box set on Ben Burtt – the guy who created the light saber sounds for Star Wars!